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                           Avionics-List Digest Archive
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                     Total Messages Posted Thu 07/10/03: 1
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     1. 08:01 PM - ELT Control Requirements  (BAKEROCB@aol.com)
 
 
 
________________________________  Message 1  _____________________________________


Time: 08:01:28 PM PST US
From: BAKEROCB@aol.com
Subject: Avionics-List: ELT Control Requirements

--> Avionics-List message posted by: BAKEROCB@aol.com

7/10/2003

Hello Fellow Builders, I am interested in knowing the definitive word on 
whether or not an ELT installed in a general aviation airplane (type certificated

or amateur built) must be able to be controlled by the pilot while in flight. 
By controlled I mean able to turn OFF or ON, or from an UNARMED state to an 
ARMED state. Further, must the pilot be automatically informed (by lights or 
other means) by the ELT when it is transmitting?

There seems to be a general presumption that there is a requirement for in 
flight control capability and some ELT's being sold have remote cable extensions

that permit this control. Some also provide a warning light when transmitting.

But there is nothing in FAR Sec. 91.207 that states those requirements. There 
is nothing in TSO-C91a that states those requirements, but this TSO like so 
many others is a very superficial document and the meat of the TSO's 
requirements are found in the references to the TSO. 

TSO-91a references Radio Technical Commission for Aeronautics (RTCA) Document 
No. DO-183, "Minimum Operational Performance Standards for Emergency Locator 
Transmitters; Automatic Fixed - ELT (AF), Automatic Portable - ELT (AP), 
Automatic Deployable - ELT (AD), Survival - ELT (S); Operating on 121.5 and 243.0

Megahertz," Section 2.0, dated May 13, 1983, but I don't have access to this 
document.

I am interested in people's experience and opinions on this subject, but 
please don't make any definitive pronouncements unless you also provide specific

references.

I am currently flying a type certificated Diamond Aircraft DA20-C1 composite 
airplane that has an EBC (Emergency Beacon Corp.) EBC 502 ELT installed.** 
This ELT is mounted back in the baggage compartment behind the right seat 
occupant's right shoulder. It is within view of the pilot, but beyond his reach

during flight. It has no remote control arrangement of any kind or any warning

light when activated. It does have a separate battery that is supposed to provide

power to an audible warning when the ELT is transmitting, but I don't know if 
this audible warning can be heard over the ambient cockpit noise and through 
headset sound protection. 

If this arrangement is legal / acceptable I don't see why one would need to 
install the remote control / warning light capability that comes with an ELT 
like the ACK ELT-01 in their amateur built experimental aircraft unless there is

some requirement that I am not aware of.

Can anybody clear this up? Many thanks.

'OC' Baker,  Builder of KIS TR-1 #116 4/14/97 - ?/?/?

PS: This ELT has one puny little thin vertical wire antenna sticking up out 
of the top of it. No fancy coil in the antenna wire, no ground plane of any 
kind. Makes one wonder about all the fuss about installing radiating strips of

metal foil in order to provide a ground plane as is commonly suggested for ELT

antenna installations.